In October 1941, the U. S. Navy organized an Armed Guard to provide gun crews for duty aboard the country's 1,375 merchant ships, just as it had done in World War I. The first Armed Guard were given their 3 weeks of training at Little Creek, Virginia and the first trainees and their officers were ready to sail in November 1941, when Congress repealed the Neutrality Act and placed guns aboard merchant ships.

By war's end, Armed Guard training bases were located throughout the country, and over 144,900 men served on over 6,236 American and Allied ships.